How to launch 009 beta2 in 1920*1200?

Anyone can help me? I launched contra 009 beta2 with the launcher, but it can only displayed at 1600*1200 in game. My monitor displays in 1920*1200, so when I play this game, it has two black space in left and right side.

Anyone can help me? I launched contra 009 beta2 with the launcher, but it can only displayed at 1600*1200 in game. My monitor displays in 1920*1200, so when I play this game, it has two black space in left and right side.

Anyone can help me? I launched contra 009 beta2 with the launcher, but it can only displayed at 1600*1200 in game. My monitor displays in 1920*1200, so when I play this game, it has two black space in left and right side.

Anyone can help me? I launched contra 009 beta2 with the launcher, but it can only displayed at 1600*1200 in game. My monitor displays in 1920*1200, so when I play this game, it has two black space in left and right side.